1. Field of the Invention
This invention relates to a sliding member using a ceramics member.
Throughout this specification, a term "sliding member" includes a contact member such as valve and valve seat and a rolling member such as roller bearing. Also, a term "coating" includes a partial coating and especially includes a coating with a composition of Cu and LiF for only depressions formed on a surface of a metal member.
2. Related Art Statement
Heretofore, as for a sliding member for use in engine members, use is made of a metal material such as a heat-resistant alloy with a lubricant such as oil, because the engine members are exposed to high temperatures and also to wear due to high speed revolutions.
However, since the sliding member is used continually year after year there is an increase in the wear of the sliding member. There occurs a requirement for utilizing the sliding members without lubricant, thus causing a drawback where requirements concerning temperature and wear cannot be achieved by the metal material or that the metal member must be frequently changed.
In order to eliminate the drawbacks mentioned above, a ceramic material may be used for the sliding member. The ceramic material can endure high temperature and has high wear resistivity and high heat efficiency, but is very hard and brittle. Therefore, all the ceramic materials cannot be used for the sliding member for this purpose.
Heretofore, there has been no investigation about what ceramic material is preferable for the sliding member especially for the engine member which endures high temperatures and requires high wear resistivity, and further about what other preferable sliding member is to be brought into contact with the ceramic material.